Necrotic Wound is a uncommon Instant card from Guilds of Ravnica Promos (PGRN), collector number 79. Current market price: — (foil $0.20), TCGplayer market prices via Scryfall.
Undergrowth — Target creature gets -X/-X until end of turn, where X is the number of creature cards in your graveyard. If that creature would die this turn, exile it instead.